<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!DOCTYPE bugzilla SYSTEM "https://bugzilla.yoctoproject.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.6"
          urlbase="https://bugzilla.yoctoproject.org/"
          
          maintainer="it-coreprojects-helpdesk@linuxfoundation.org"
>

    <bug>
          <bug_id>16102</bug_id>
          
          <creation_ts>2025-12-16 16:50:47 +0000</creation_ts>
          <short_desc>Document risks and assumptions for shared &quot;downloads&quot; directories</short_desc>
          <delta_ts>2026-10-22 15:21:06 +0000</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>9</classification_id>
          <classification>Documentation</classification>
          <product>Development Manual</product>
          <component>development</component>
          <version>6.0</version>
          <rep_platform>x86</rep_platform>
          <op_sys>Multiple</op_sys>
          <bug_status>ACCEPTED</bug_status>
          <resolution></resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords></keywords>
          <priority>Medium</priority>
          <bug_severity>normal</bug_severity>
          <target_milestone>6.2</target_milestone>
          
          
          <everconfirmed>1</everconfirmed>
          <reporter name="Randy MacLeod">randy.macleod</reporter>
          <assigned_to name="Paul Barker">paul</assigned_to>
          <cc>antonin.godard</cc>
    
    <cc>daniel.ammann</cc>
    
    <cc>richard.purdie</cc>
          
          
          <cf_os>---</cf_os>
          <cf_regression_type>---</cf_regression_type>
          
          <cf_docchange>Yes (doc changes required)</cf_docchange>

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>103574</commentid>
    <comment_count>0</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2025-12-16 16:50:47 +0000</bug_when>
    <thetext>In the Dec 16, 2025 YP Tech call, 
Peter pointed out that for for builds that share the downloads directory, 
git recipes, could corrupt the local copy of a git clone.
I think this involves a malicious user more than two builds racing.

Peter plans to document this risk and explain how people should deal 
with the risk and verify their local downloads directory.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>103576</commentid>
    <comment_count>1</comment_count>
    <who name="Peter Kjellerstedt">peter.kjellerstedt</who>
    <bug_when>2025-12-16 16:59:49 +0000</bug_when>
    <thetext>The case we have is that we have a shared download cache. The we have normal CI builds that use it and also official release builds. The assumption has been that it is fine to share the download cache between these types of builds since everything is protected by either Git SHA-1s, or SRC_URI[sha256sum] checksums. 

However, what we have realized is that a malicious user can modify the actual Git blobs that are stored in the download cache without Git noticing this has happened when fetching the repository into the build tree. Thus the malicious user can run a developer build in CI that does this, and it will later affect an official release build.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>105843</commentid>
    <comment_count>2</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2026-06-11 15:20:33 +0000</bug_when>
    <thetext>Do you have a proposal for how we should detect this rather than only documenting the risk?</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>106459</commentid>
    <comment_count>3</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2026-08-06 15:21:16 +0000</bug_when>
    <thetext>Paul and Richard to write a draft for Antonin.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>